I admit being a little biased because I used the 580 lightning as well, but I really feel like the lightning is hands down the best 680 on the market if you're interested in pushing the limits in overclocking. If you consider the other options, none offer what the lightning does for the price - the other option is the classified from EVGA which (from newegg reviews) is getting worse out of the box overclocks and costs 760$ with EV Bot (required for overvoltage).

My 680 lightning gets 1352mhz with no overvoltage and past 1400 with overvoltage so i'm really enjoying it